Apparatus for the manufacture of emulsions

ABSTRACT

The disclosure relates to apparatus for the manufacture of emulsions in which a first liquid is gradually introduced into a second liquid while stirring. Due of the two liquids, for example a fat or wax, may be heated, for example to melt it, and the other liquid may be relatively cold. In order to ensure good emulsifying in spite of such temperature differences, the apparatus comprises nozzle means arranged to introduce said first liquid in fine distribution into the draw in area of a rotating stirring member running in the second liquid, which stirring member is the rotor part of a mixing and homogenizing tool that also has a stator surrounding the rotor.

United States Patent 11 1 Brogli et a]. Dec. 9, 1975 [5 1 APPARATUS FORTHE MANUFACTURE OF 2,142,344 1/1939 Bowen .1 259/23 EMULSIONS 2,502,7784/1950 Collins et al 1. 252/359 D 2,673,075 3/l954 Borck; 252/359 Clnvemorsi Hans g Gotthelfslrasse 42, 3,415,650 l2/l968 Frame et al259/23 x a Werner F. Brogli, 3,692,283 9/1972 Sauer et a1 259/24 E22:FOREIGN PATENTS OR APPLICATIONS [22] Filed: Aug- 23, 1973 340,82l l/l93lUnlled Kmgdom 259/96 [2l] Appl. No 391,158 Primary Examiner-Jack SoferRelated us. Application Dam Attorney, Agent, or Firm-Eyre, Mann & Lucas[63 Continuation-inart of Ser. No. I45, 53,

1 1971, Pat. No. 791,984. 8 May m [57] ABSTRACT The disclosure relatesto apparatus for the manufac- [30] Foreign Application Priority Datature of emulsions in which a first liquid is gradually in- June 1, 1970Switzerland 859/70 troduced into a second liquid while stirring Due ofthe two liquids, for example a fat or wax, may be 52 us. (:1 252/359 c;252/359 D; 259/23; heated, for example to melt n and the other liquid 259 may be relatively cold. In order to ensure good emulsi- [51] I t, CUB011? 7/16; B01 13 00; 3 5 fying in spite of such temperaturedifferences, the ap- [58] Field of Search 252/359 C, 359 D, P compl'isesnozzle means arranged introduce 252/3()(,-3]3 NG; 259/23 9 30 said firstliquid in fine distribution into the draw in area of a rotating stirringmember running in the sec- [5 References Cited ond liquid, whichstirring member is the rotor part of UNITED STATES PATENTS a mixing andhomogenizing tool that also has a stator surrounding the rotor,l,727,l52 9/1929 Winkler 259/DIG. 30 1,757,065 5/1930 Warsop et al.252/359 (3 3 Claims, 5 Drawing Figures STIRRER U.S. Patent Dec. 9, 1975Sheet 1 of2 3,925,243

L 0 TO BE ULSIFIED (LTBE) LIQUID BATH TO BE MIXED U.S. Patent Dec. 9,1975 Sheet 2 of2 3,925,243

F7 3 Q/STIRRER .rSTIRREH 3 '-STIRRER APPARATUS FOR THE MANUFACTURE OFEMULSIONS CROSS-REFERENCE This application is a continuation-in-part ofSer. No. 145,853 which was filed May 21, 1971 now US. Pat. No. 3,791,984issued Feb. 12, 1974.

BACKGROUND OF THE INVENTION This invention relates to the manufacture ofan emulsion.

In the manufacture of emulsions it is usual to insert the media to beemulsified at temperatures which differ only a little, or as far aspossible not at all, from one another.

If, for example, it is desired to produce an emulsion with fat or wax itis as a rule necessary to melt the fat or wax. Then an aqueous liquidcan be allowed to run gradually whilst stirring into the melt, which isheated for example at about 80C, whereby experience has always shownthat a satisfactory emulsion can only be obtained if the aqueous liquidsupplied is likewise heated, for example to about 82C. From thisexperience there has resulted the procedural rule already mentioned.

On the other hand it can be noted that emulsions are as a rule stableagainst decomposition only at temperatures below a certain specificvalue. This value may, for example, according to the type and quantityof emulsifiers and other additions used, be at about to or C. Iftherefore according to known methods an emulsion has been produced froma fat or wax fusion and a likewise heated aqueous liquid then it is forthe most part necessary to cool the emulsion with further stirring untilbelow the stability limit in order to prevent a decomposition of theemulsion. This cooling may under certain circumstances require severalhours whilst the actual emulsifying could frequently be carried out in afew minutes. The cooling thus makes the manufacture of the emulsionuneconomic because the emulsifying devices remain filled for a very longtime and it also renders a continuous operation practically impossible.Attempts have been made to accelerate the cooling by means of coolingsurfaces; this however has frequently the drawback that certainsubstances, for example wax, become deposited on the cooling surfacesand are thereby drawn out of the emulsion.

It has now been found that under certain circumstances and conditionsthe traditional procedure aforementioned can be disregarded withresultant advantages.

The parent application Ser. No. 145,853 thus claims a method for themanufacture of an emulsion in which.

a first liquid is gradually introduced while stirring into a secondliquid which has been heated to a temperature which is above the limittemperature up to which the finished emulsion is stable and above thesolidification temperature of this first liquid, which method ischaracterized in that the first liquid, at a temperature below the saidlimit temperature and/or solidification temperature, is introduced infine distribution in the entry area of a stirring member which runs inthe heated second liquid.

The first liquid may be suitably introduced at a temperature which is atleast 25C preferably at least 50C below the temperature at which thesecond liquid, for example melted fat or wax, has been heated. In mostcases the first liquid, for example an aqueous liquid,

may be practically cold, that is have room temperature or tap watertemperature. In this way the mixture temperature of the finishedemulsion after the total quantity provided of the first liquid has beenintroduced may be below the said limit temperature so that no morecooling with stirring is necessary.

It is also possible to heat the first liquid, for example when this is afat or wax, and introduce it into a cold second liquid in the mannerdescribed above.

SUMMARY OF THE INVENTION The present application relates to apparatussuitable for carrying out the method for making emulsions describedabove. The apparatus comprises a mixing and homogenizing tool with anannular stator and a stirring member disposed in the stator which isrotatable in order to draw a medium from an inlet side of the stator tomix it thoroughly and thrust it out at an outlet side, and it ischaracterized in that at least one nozzle is dis posed at the inlet sideof the stator with an opening directed towards the draw in area of thestirring member, which nozzle is connected to a supply pipe for theliquid which is to be introduced and emulsified.

The nozzle must be arranged close to the stirring member, in a regionwhere the medium flow rate is high, in such a manner that the entireamount of liquid supplied by it in fine distribution is at once drawninto the homogenizing tool and completely emulsified, and thetemperature equalization between this liquid and the medium occurssubstantially only in the homogenizing tool.

The nozzle may, for example, have a fine annular gap surrounding thedraw in area of the stirring member. Instead of this there could also bearranged around the draw in area a ring of nozzles in order to obtainthe required fine distribution of the first liquid.

In a particularly suitable construction the nozzle having an annular gapmay be fonned by two annular plates which are fixed to the inlet side ofthe stator. The annular space bounded by these plates may be divided inthe peripheral direction into two or more partial spaces which are eachconnected to a separate supply pipe so that several components of thefirst liquid or several first liquids can be introduced separately intothe draw in area of the stirring tool. Furthermore the annular gap ofthe nozzle may be arranged surrounding the draw in area of the stirringmember such that the medium drawn in by the stirring member and flowingpast the gap produces a low pressure in the nozzle in order to draw inthe first liquid through the supply pipe so that the use of a pumpingdevice specifically for the first liquid can be dispensed with. In orderto achieve an improved thorough mixing of the medium in the stirringtool a third annular plate may be suitably disposed on the stator whichbounds a second nozzle space likewise leading into an annular gap whichis directly adjacent the mixing chamber in the mixing tool and isconnected to this via openings in the uppermost plate. Thereby a portionof the medium is turned around in the mixing chamber and fed again tothe stirring member through the said openings and the additional annularnozzle.

The necessary fine distribution of the liquid introduced into the drawin area of the stirring member can be attained suitably also with arotatable nozzle wheel which is disposed on the inlet side of the statorand connected to a supply pipe.

DESCRIPTION OF PREFERRED EMBODIMENTS Embodiments of the apparatusaccording to the invention are explained by way of example in thefollowing description with reference to the drawings. In the drawings:

FIG. 1 shows diagrammatically a vertical section through a stirring toolwith a ring nozzle on the inlet side,

FIG. 2 shows diagrammatically a horizontal section through a particularembodiment of the ring nozzle according to FIG. I and FIGS. 3, 4 and 5show diagrammatic sections through stirring tools with nozzles arrangeddifferently on the inlet side.

The stirring and homogenizing tool shown in FIG. 1 has an annular statorI which is carried via vertical bars 2 on a stand not shown and isimmersed, from above, into a medium in a vessel likewise not shown. Inthe stator l a rotor or stirring member 3 is disposed which may berotated by means of a shaft 4 around its vertical axis and then sucks,mixes and thrusts upwards medium from below as indicated by the arrows.

On the underside of the stator 1 three annular plates 5, 6 and 7 arefixed, spaced apart from one another, and enclosing between them annularchambers 8 and 9. These annular chambers are' closed on the outerperiphery but open inside towards the draw in area of the stirringmember 3 via annular nozzle gaps 8a and 9a. The upper annular chamber 8is in communication,.via openings in the plate 5, with the mixingchamber in the stator 1 so that material to be mixed is supplied to thisannular chamber. The lower annular chamber 9 is connected to a supplypipe 10 for a liquid to be emulsified which is fed in fine distributionthrough the corresponding annular gap 9a to the material to be mixed,which is sucked in by the stirring member 3. The annular gap may have aheight of about 0.5 mm to a few mm, for example 3 mm, according to thedimensions of the stirring tool.

In the example shown the annular gaps 8a and 9a are so arranged, and theplates 5, 6 and 7 are so formed on their inner edges, that the mediumsucked by the stirring member flowing past the annular gaps produces inthese a low pressure in the manner of a jet pump. This has the advantagethat the liquid to be emulsified is sucked automatically through thepipe 10. It would of course also be possible to convey the liquidthrough the pipe 10 with pressure or maintain a vacuum above thematerial to be mixed, with the use of a closed vessel.

According to FIG. 2 if desired the annular space 9 above the plate 7 maybe divided by means of radial partitions 9b into several sector likeareas and these separate areas may be connected to separate supply pipes10, 10 and 10". In this way several different liquids to be emulsifiedcan then be fed separately simultaneously. The arrangement shown isintended for three different liquids in mutual quantity ratios 50percent; 30 percent; percent (through the pipes 10 and 10 and 10respectively).

If desired the liquid could be fed from the supply pipe also via anannularly arranged rim of individual nozzles instead of through thenozzle ring gap 9a. It is merely essential for the liquid to beemulsified to be introduced in as fine a distribution as possibledirectly into the draw in area of the stirring member.

Other different possible arrangements of nozzles are showndiagrammatically, by way of example, in FIGS.

3, 4 and 5. Here also the nozzles are arranged on the inlet side of astirring and homogenizing tool which, like that shown in FIG. 1, has astator l and a rotor or stirring member 3. The nozzle openings aredirected towards the draw in area of the stirring member 3 in order tointroduce the second liquid to be emulsified in fine distribution inthis draw in area.

According to FIG. 3 several separate single nozzles 16 are peripherallydisposed on the inlet side of the stator 1, connected to individualsupply pipes 20.

According to FIG. 4 an annular nozzle 26 is disposed below the stator 1.An annular chamber 29 in this nozzle 26 is connected to a supply pipe30. The chamber 29 is in communication with the draw in area of thestirring member 3 via a plurality of nozzle openings 29a on the insideof the ring nozzle body.

According to FIG. 5 there is used, for the supply of the liquid to beemulsified in the draw in area of the stirring member 3, a rotatable anddrivable nozzle wheel 36 which is disposed under the stirring member 3and approximately coaxially with this and to which the liquid is fed viaa supply pipe 40. The nozzles of this nozzle wheel are directed upwardlytowards the stirring member 3.

Emulsions can be made as follows with the apparatus described.

There is placed in a vessel, in which the stirring tool is immersed, aliquid which for any reason, for example because it would be congealedat room temperature, is heated to a temperature which is above the limittemperature up to which the emulsion to be made is stable and above thecoagulation temperature or solidification temperature of the liquid.This liquid may, for example, be a melted fat or wax at a temperature ofabout C. The stirring tool is then allowed to run so that the liquid iswhirled or rolled around. Another liquid, which is to be emulsified, forexample an aqueous solution, is now supplied via the supply pipe. Thisother liquid has a temperature below the said limit temperature and/orbelow the coagulation temperature or solidification temperature of theliquid in the vessel. One may also, for example, with an arrangementaccording to FIG. 2 or with single nozzles according to FIG. 3 supplyseveral liquids simultaneously; in this case at least one and preferablyall of the liquids supplied should then have a temperature below thesaid value. As a rule the liquid to be emulsified may be introducedcold, that is at about room temperature or tap water temperture. In themanner stated immediately with the commencement of the introduction ofthe liquid to be emulsified, so long as the liquid in the vessel isstill hot, a good parent emulsion can be obtained. With increasingquantity of liquid introduced the temperature of course dops gradually.Surprisingly however it is nevertheless possible without difficulties toemulsify further quantities of cold liquid after the parent emulsion" isformed, although as a rule small quantities of suitable emulsifier mustbe added.

It is also possible to interchange the heated liquid and the relativelycold liquid, i.e. the cold liquid may be placed in the vessel and theheated liquid, such as fat or wax, may be gradually introduced via thesupply pipe and nozzle. If it is intended to carry out this mode ofoperation, heating means may be provided for heating the supply pipe.

It is possible in the manner described to emulsify a liquid in almostany desired quantity into the liquid in the vessel. One may, forexample, produce an emulsion from fat and an aqueous solution in whichthe constituent parts are present in the weight ratio of 3 l to l 3 andwhich is solid at room temperature in that the fat forms the outerphase. One may however also increase the quantity of the aqueous liquidup to a weight ratio of 2 8 to l 9. The emulsion then changes, that is,the fat forms the inner phase so that the finished emulsion is liquid atroom temperature.

One liquid is thus always used at a temperature which is substantiallylower than the temperature of the heated other liquid, for example, byat least 25C preferably at least 50C lower. In most cases the coldliquid may be suitably used at room temperature or tap water temperatureIn the manner described an emulsion may as a rule be produced in a fewminutes. After completion of the introduction of the second liquid theemulsion is ready and no longer requires cooling whilst stirring incontradistinction to the cooling times of several hours which werefrequently heretofore necessary in the manufacture of emulsions inaccordance with known methods and in known apparatus which did notpermit the use of liquids at substantially different temperatures.

What is claimed is:

1. Apparatus for the manufacture of an emulsion from a first bath liquidand a second feed liquid immiscible with said first liquid, one of saidliquids being heated and the other liquid being relatively cool, saidapparatus comprising:

a mixing and homogenizing tool immersed in said first liquid comprisingan annular stator and a stirring member disposed in said stator, thestator having an inlet side and an outlet side, and said stirring memberbeing rotatable to form a draw in area for drawing said first liquidfrom said inlet side into said mixing and homogenizing tool,

and at least one nozzle disposed at said inlet side of said stator andhaving a nozzle opening of shape and position to introduce said secondliquid in fine distribution in the draw in area of said stirring memberso that said second liquid is drawn into said mixing and homogenizingtool together with said first liquid and thoroughly mixed therewith insaid tool before said liquids are thrust out at said outlet side,

said nozzle having an annular gap which is formed by the innerperopheries of coaxial annular plates which are fixed to said inlet sideof said stator, said nozzle gap being divided in the peripheraldirection into at least two sector-like chambers each of which isconnected to a separate supply pipe for different liquids.

2. Apparatus for the manufacture of an emulsion from a first bath liquidand a second feed liquid immiscible with said first liquid, one of saidliquids being heated and the other liquid being relatively cool, saidapparatus comprising:

a mixing and homogenizing tool immersed in said first liquid comprisingan annular stator and a stirring member disposed in said stator, thestator having an inlet side and an outlet side, sand said stirringmember being rotatable to form a draw in area for drawing said firstliquid from said inlet side into said mixing and homogenizing tool,

and at least one nozzle disposed at said inlet side of said stator andhaving a nozzle opening of shape and position to introduce said secondliquid in fine distribution in the draw in area of said stirring memberso that said second liquid is drawn into said mixing and homogenizingtool together with said first liquid and thoroughly mixed therewith insaid tool before said liquids are thrust out at said outlet side,

said nozzle having an annular gap which is formed by the innerperipheries of coaxial annular plates which are fixed to said inlet sideof said stator, said annular gap being disposed surrounding said draw inarea of said stirring member in such manner that said first liquidsucked by the stirring member and flowing past the annular gap producesa low pressure in the noule in order to suck in said second liquidthrough a supply pipe connected to said nozzle.

3. Apparatus for the manufacture of an emulsion from a first bath liquidand a second feed liquid immiscible with said first liquid, one of saidliquids being heated and the other liquid being relatively cool, saidapparatus comprising:

a mixing and homogenizing tool immersed in said first liquid comprisingan annular stator and a stirring member disposed in said stator, thestator having an inlet side and an outlet side, and said stirring memberbeing rotatable to form a draw in area for drawing said first liquidfrom said inlet side into said mixing and homogenizing tool,

and a ring of separate nozzles disposed annularly around said draw inarea of said stirring member,

said nozzles having nozzle openings of shape and position to introducesaid second liquid in fine distribution in the draw in area of saidstirring member so that said second liquid is drawn into said mixing andhomogenizing tool together with said first liquid and thoroughly mixedtherewith in said tool before said liquids are thrust out at said outletside.

I I l i

1. Apparatus for the manufacture of an emulsion from a first bath liquidand a second feed liquid immiscible with said first liquid, one of saidliquids being heated and the other liquid being relatively cool, saidapparatus comprising: a mixing and homogenizing tool immersed in saidfirst liquid comprising an annular stator and a stirring member disposedin said stator, the stator having an inlet side and an outlet side, andsaid stirring member being rotatable to form a draw in area for drawingsaid first liquid from said inlet side into said mixing and homogenizingtool, and at least one nozzle disposed at said inlet side of said statorand having a nozzle opening of shape and position to introduce saidsecond liquid in fine distribution in the draw in area of said stirringmember so that said second liquid is drawn into said mixing andhomogenizing tool together with said first liquid and thoroughly mixedtherewith in said tool before said liquids are thrust out at said outletside, said nozzle having an annular gap which is formed by the innerperopheries of coaxial annular plates which are fixed to said inlet sideof said stator, said nozzle gap being divided in the peripheraldirection into at least two sector-like chambers each of which isconnected to a separate supply pipe for different liquids.
 2. APPARATUSFOR THE MANUFACTURE OF AN EMULSION FROM A FIRST BATH LIQUID AND A SECONDFEED LIQUID IMMISCIBLE WITH SAID FIRST LIQUID, ONE OF SAID LIQUIDS BEINGHEATED AND THE OTHER LIQUID BEING RELATIVELY COOL, SAID APPARATUSCOMPRISING: A MIXING AND HOMOGENIZING TOOL IMMERSED IN SAID FIRST LIQUIDCOMPRISING AN ANNULAR STATOR AND A STIRRING MEMBER DISPOSED IN SAIDSTATOR, THE STATOR HAVING AN INLET SIDE AND AN OUTLET SIDE, SAND SAIDSTIRRING MEMBER BEING ROTATABLE TO FORM A DRAW IN AREA FOR DRAWING SAIDFIRST LIQUID FROM SAID INLET SIDE INTO SAID MIXING AND HOMOGENIZINGTOOL, AND AT LEAST ONE NOZZLE DISPOSED AT SAID INLET SIDE OF SAID STATORAND HAVING A NOZZLE OPENING OF SHAPE AND POSITION TO INTRODUCE SAIDSECOND LIQUID IN FINE DISTRIBUTION IN THE DRAW IN AREA OF SAID STIRRINGMEMBER SO THAT SAID SECOND LIQUID IS DRAWN INTO SAID MIXING ANDHOMOGENIZING TOOL TOGETHER WITH SAID FIRST LIQUID AND THOROUGHLY MIXEDTHEREEITH IN SAID TOOL BEFORE SAID LIQUIDS ARE THRUST OUT AT SAID OUTLETSIDE, SAID NOZZLE HAVING AN ANNULAR GAP WHICH IS FORMED BY THE INNERPERIPHERIES OF COAXIAL ANNULAR PLATES WHICH ARE FIXED TO SAID INLET SIDEOF SAID STATOR, SAID ANNULAR GAP BEING DISPOSED SURROUNDING SAID DRAW INAREA OF SAID STIRRING MEMBER IN SUCH MANNER THAT SAID FIRST LIQUIDSUCKED BY THE STIRRING MEMBER AND FLOWING PAST THE ANNULAR GAP PRODUCESA LOW PRESSURE IN THE NOZZLE IN ORDER TO SUCK IN SAID SECOND LIQUIDTHROUGH A SUPPLY PIPE CONNECTED TO SAID NOZZLE.
 3. Apparatus for themanufacture of an emulsion from a first bath liquid and a second feedliquid immiscible with said first liquid, one of said liquids beingheated and the other liquid being relatively cool, said apparatuscomprising: a mixing and homogenizing tool immersed in said first liquidcomprising an annular stator and a stirring member disposed in saidstator, the stator having an inlet side and an outlet side, and saidstirring member being rotatable to form a draw in area for drawing saidfirst liquid from said inlet side into said mixing and homogenizingtool, and a ring of separate nozzles disposed annularly around said drawin area Of said stirring member, said nozzles having nozzle openings ofshape and position to introduce said second liquid in fine distributionin the draw in area of said stirring member so that said second liquidis drawn into said mixing and homogenizing tool together with said firstliquid and thoroughly mixed therewith in said tool before said liquidsare thrust out at said outlet side.